Joint estimation of location and signal parameters for an LFM emitter

This paper considers the localization of an emitter employing linear frequency modulation (LFM) signal with unknown parameters. The proposed approach is based on jointly estimating the emitter position along with the transmitted signal parameters. In the maximum likelihood context, the joint estimation problem is shown to translate into an optimization search in a six-dimensional space. In many practical applications, such a search may be too computationally expensive to run in real-time. We suggest a sub-optimal yet fast solution based on combining the direct position determination (DPD) method with a short time Fourier transform (STFT). Despite the sub-optimality, the proposed DPD-STFT method is able, with low complexity, to achieve higher localization accuracies than methods that are based on estimation of emitter position only (regardless of signal parameters). Indeed, due to joint estimation of emitter position and the transmitted signal parameters, our method harnesses more information for localization purposes. Simulation results show that the proposed method outperforms the existing DPD algorithms, in terms of localization error.